clarc/CLAUDE.md

# clarc

Self-hosted remote control for Claude Code. Wrap CLI in PTY, stream output to server, approve prompts from phone.

## Project

Pure Bun stack: no frameworks, minimal dependencies. Target ~1000-1500 lines total.

Core tech:

- bun-pty for PTY wrapper (FFI to Rust, pre-built binaries)
- bun:sqlite for persistence
- Bun.serve() for HTTP + WebSocket + SSE
- plain text output (no xterm.js) for mobile-friendly display

## Terminal Emulation

Output processing uses @xterm/headless for proper VT100 emulation:
- src/terminal.ts - headless terminal wrapper
- One terminal instance per session (created on auth, disposed on close)
- serializeAsHTML() produces HTML for SSE broadcast
- trimHtmlOutput() removes empty trailing rows for cleaner display

See docs/terminal-emulation.md for design rationale.

## References

Inspiration and patterns to steal from:

| Source     | Path             | What to look at                                                    |
| ---------- | ---------------- | ------------------------------------------------------------------ |
| crabigator | `../crabigator/` | Architecture, WebSocket protocol, cloud client, session management |
| bun-pty    | `../bun-pty/`    | PTY API, spawn patterns, event handling                            |

Key files in crabigator:

- `src/cloud/client.rs` - WebSocket connection, reconnection logic
- `src/cloud/events.rs` - event types for streaming
- `src/capture.rs` - output capture patterns
- `workers/crabigator-api/src/session-do.ts` - session state management

Key files in bun-pty:

- `src/index.ts` - spawn API, IPty interface
- `src/terminal.ts` - FFI bindings (for understanding internals)

## Contribution policy

If bun-pty needs changes, fork and contribute upstream. Don't vendor or patch locally.

## Workflow

After making changes:

```bash
just check  # lint + typecheck + test
```

Commit after each logical change. One change = one commit. Keep commits atomic.

### Code review

Run code review after completing a phase or significant chunk of work:
- Use `superpowers:code-reviewer` agent
- Provide: what was implemented, git range (base SHA to head SHA), requirements
- Fix critical/important issues before moving on
- Minor issues can be noted and deferred

Review loop: implement → just check → code review → fix issues → re-review if needed → pause for user.

## Bun defaults

- Use `bun <file>` instead of `node <file>` or `ts-node <file>`
- Use `bun test` instead of `jest` or `vitest`
- Use `bun build <file.html|file.ts|file.css>` instead of `webpack` or `esbuild`
- Use `bun install` instead of `npm install` or `yarn install` or `pnpm install`
- Use `bun run <script>` instead of `npm run <script>` or `yarn run <script>` or `pnpm run <script>`
- Use `bunx <package> <command>` instead of `npx <package> <command>`
- Bun automatically loads .env, so don't use dotenv.

## APIs

- `Bun.serve()` supports WebSockets, HTTPS, and routes. Don't use `express`.
- `bun:sqlite` for SQLite. Don't use `better-sqlite3`.
- `Bun.redis` for Redis. Don't use `ioredis`.
- `Bun.sql` for Postgres. Don't use `pg` or `postgres.js`.
- `WebSocket` is built-in. Don't use `ws`.
- Prefer `Bun.file` over `node:fs`'s readFile/writeFile
- Bun.$`ls` instead of execa.

## Testing

Use `bun test` to run tests.

```ts#index.test.ts
import { test, expect } from "bun:test";

test("hello world", () => {
  expect(1).toBe(1);
});
```

## Frontend

Use HTML imports with `Bun.serve()`. Don't use `vite`. HTML imports fully support React, CSS, Tailwind.

Server:

```ts#index.ts
import index from "./index.html"

Bun.serve({
  routes: {
    "/": index,
    "/api/users/:id": {
      GET: (req) => {
        return new Response(JSON.stringify({ id: req.params.id }));
      },
    },
  },
  // optional websocket support
  websocket: {
    open: (ws) => {
      ws.send("Hello, world!");
    },
    message: (ws, message) => {
      ws.send(message);
    },
    close: (ws) => {
      // handle close
    }
  },
  development: {
    hmr: true,
    console: true,
  }
})
```

HTML files can import .tsx, .jsx or .js files directly and Bun's bundler will transpile & bundle automatically. `<link>` tags can point to stylesheets and Bun's CSS bundler will bundle.

```html#index.html
<html>
  <body>
    <h1>Hello, world!</h1>
    <script type="module" src="./frontend.tsx"></script>
  </body>
</html>
```

With the following `frontend.tsx`:

```tsx#frontend.tsx
import React from "react";
import { createRoot } from "react-dom/client";

// import .css files directly and it works
import './index.css';

const root = createRoot(document.body);

export default function Frontend() {
  return <h1>Hello, world!</h1>;
}

root.render(<Frontend />);
```

Then, run index.ts

```sh
bun --hot ./index.ts
```

For more information, read the Bun API docs in `node_modules/bun-types/docs/**.mdx`.